Resolve duplicated page objects (fixes #268)

When linearizing a file or getting the list of all pages in a file,
detect if the pages tree contains a duplicated page object and, if so,
shallow copy it. This makes it possible to have a one to one mapping
of page positions to page objects.

1 files changed, 3 insertions, 0 deletions

diff --git a/libqpdf/QPDF_optimization.cc b/libqpdf/QPDF_optimization.cc
index f282e5f3..ecece7db 100644
--- a/libqpdf/QPDF_optimization.cc
+++ b/libqpdf/QPDF_optimization.cc
@@ -156,6 +156,9 @@ QPDF::pushInheritedAttributesToPage(bool allow_changes, bool warn_skipped_keys)
         return;
     }
 
+    // Calling getAllPages() resolves any duplicated page objects.
+    getAllPages();
+
     // key_ancestors is a mapping of page attribute keys to a stack of
     // Pages nodes that contain values for them.
     std::map<std::string, std::vector<QPDFObjectHandle> > key_ancestors;